Unionists' threats to collapse the Stormont administration over a Government scheme to deal with on-the-run republicans are an attempt to distract from the fact they knew the process existed, Martin McGuinness has claimed.
Responding to Democratic Unionist (DUP) First Minister Peter Robinson's threat to resign over the issue - a move that would trigger an Assembly election - the Sinn Fein Deputy First Minister insisted such drastic action would achieve nothing.
"I think Peter is well aware of my view that this is a time for steady leadership, this is a time for calm nerves, this is a time for solutions to the present scenario we find ourselves," he said.
"This is certainly not the time - though I don't fear it at all - for an election."
Mr McGuinness said he would never voluntarily walk away from the devolved institutions.
Details of 187 letters sent to so-called on-the-run republicans (OTRs), assuring them they would not be prosecuted if they returned to Northern Ireland, emerged when a case against a man charged with the 1982 IRA Hyde Park bomb collapsed.
But DUP claims that it was unaware of the deal between the Government and Sinn Fein on OTRs have been questioned after it emerged that a senior Police Service of Northern Ireland (PSNI) officer briefed members of the PSNI's scrutiny body - the NI Policing Board - on elements of the scheme in 2010, albeit without mention of the letters.
DUP members were present at the Policing Board meeting. The issue was also mentioned in the high-profile 2009 Eames-Bradley report on dealing with the legacy of the Troubles.
Mr McGuinness said: "I think that the angst among unionist politicians is more centred around the common belief out there in society and in the media that they knew all about this.
"They may not have known about the letters, but they knew about the scheme and they knew that these people who were described as on-the-runs were being processed.
"I think that's where the annoyance comes from."
Mr McGuinness insisted letters were sent only to those people against whom police did not have evidence to prosecute. He claimed the fact that other republicans had been unable to obtain letters proved there was no suggestion the documents amounted to an amnesty.
He said: "A very important part about this issue is that those names that were put forward, those people were told no charges could be proceeded with or brought against them.
"There were also another smaller number of names that people were told that charges would be proceeded with if they returned to the north.
"So that information blows out of the water this argument of amnesty or immunity or get out of jail card."
Mr Robinson has effectively given the Government 24 hours to respond to his demand for a public inquiry into the issue.
The First Minister, who has claimed he and other Stormont ministers were kept in the dark over the OTR deal, has said he will walk away from the coalition Executive if a judicial inquiry is not called and the letters rescinded.
Having asked for the Assembly to be recalled tomorrow, he has made clear the contents of a motion he would put before the House would depend on the Government's response to his demands - prompting the prospect of a resignation and subsequent election.
Downing Street said it would not pre-empt the discussions being held today and refused to say what timetable it was working to.
The Prime Minister's official spokesman said: "When serious concerns are raised, it's a matter of urgency to consider these things but discussions are ongoing. I'm not going to try and pre-judge how those will pan out."
Deputy Prime Minister Nick Clegg said the Government was looking "urgently" at Mr Robinson's call for a judicial inquiry, but warned against allowing the Downey case to escalate into a "full-blown political crisis".
He also acknowledged that the London administration should have been more open about the administrative scheme with Mr Robinson and his colleagues.
"Clearly, with the benefit of hindsight, it would have been much better to have an open discussion at an earlier stage with Peter Robinson and his administration on this legacy system that had been set up many years ago by the previous Labour government," he said.
The details of the deal emerged during the failed prosecution of John Downey, from Donegal, over the Hyde Park attack.
The 62-year-old denied murdering four soldiers in the bombing in London.
The case against him was ended because Government officials mistakenly sent him a letter in 2007 telling him he was no longer a wanted man.
While the errors that resulted in Mr Downey receiving the letter have led to an apology from the PSNI, a political crisis has erupted at Stormont over the wider issue of why the Government was sending out any assurance letters - and allegedly without the knowledge of the majority of Stormont politicians.
The deal was apparently struck between Sinn Fein and the previous Labour government after an effort to legislate on the issue of OTRs failed.
But of 187 letters sent out, 38 were issued since the coalition Government took power in 2010.
With justice powers devolved back to Stormont just before the last general election, the anger of many Assembly members has been intensified by the fact the policy seemingly continued to be pursued by the Northern Ireland Office when law and order responsibilities rested with the power-sharing Executive.
Former Ulster Unionist first minister Lord Trimble has insisted he knew "absolutely nothing" of the letters, and said he believed the Government conspired with Sinn Fein.
"I would dearly love to know who signed off on that," he said. "I don't know anybody who knew about it."
Mr Robinson, who met Ms Villiers at Hillsborough Castle last night, claimed the deal also involved republicans who had committed offences being granted royal pardons.
"It appears that we are not just dealing with on-the-runs who received letters but we are also dealing with people who received the royal prerogative of mercy, that indicates there were offences involved," he said.
"So we are not talking just about people who it is believed that the police did not have sufficient evidence to make a prosecution stick - that makes it a very serious matter."
Asked about claims that royal pardons had been given, the spokesman for the Prime Minister replied: "Clearly, all the issues that the First Minister raises will, of course, be looked at."
No 10 refused to be drawn on when the Prime Minister knew about the 38 letters that had been sent out since the coalition took power.
The spokesman added: "In terms of any possible next steps, there are discussions that are ongoing and I don't think the right thing for me to do it pre-empt them."
A letter was sent to Mr Downey by the NIO on advice from the PSNI that he was not wanted in connection with any terror offences. But Mr Downey was being actively sought by the Metropolitan Police.
The recent legal wrangle raised questions with the PSNI which, the court heard, knew about the UK arrest warrant for Mr Downey but did nothing to correct the error of 2007 in sending the letter.
The judge at the Old Bailey, Mr Justice Sweeney, threw the case out after Mr Downey's lawyer successfully argued at the 11th hour that a trial would represent an abuse of process given the written assurances he had received.
The Crown has announced that it would not appeal against the decision.
On July 20 1982, a car bomb left in South Carriage Drive killed four soldiers as they rode through Hyde Park in central London to the Changing of the Guard.
The explosion killed Roy Bright, Denis Daly, Simon Tipper and Jeffrey Young, and injured other members of the Royal Household Cavalry. Seven horses were also killed as the soldiers travelled from their barracks to Buckingham Palace. Another horse, Sefton, survived terrible injuries and became a British national hero.
The investigation into the bombing led police to Mr Downey, through fingerprints on parking tickets and a description given by witnesses of two men carrying out reconnaissance in the area before the attack.
An arrest warrant was issued, but it was decided not to seek Mr Downey's extradition from the Irish Republic in 1989, in part due to the lack of strong evidence against him, the court was told.
In 2007, Mr Downey received assurance that he was not at risk of prosecution as part of the OTR scheme.